Steel girder-frame for reinforced-concrete girders.



No. 887,863.- PATENTED MAY 19, 1908. E. N. & R. E. SPAULDING. STEEL GIRDER FRAME FOR REINFORCED GONGRETB GIRDERS.

PPPPPP ATION FILED JULY 26. 1907.

N F s) 2; K \E u carried thereby decreases; second, to utilize UNITED STATES PATEN. FFICE.

EDGAR. N. SPAULDING AND RALPILE. SPAULDING, OF SUFFIELD, CONNECTICUT.

STEEL GIRDER-FRAME FOR REINFORCED-CONCRETE GIRDERS.

Specification of Letters Patent.

Patented May 19, 1908.

Application filed J 119 26, 1907. Serial No. 385,763.

central lon itu inal top stay bar with two longitudinal bottom tension bars, and also employ inclined tie braces, the latter being at the ends of said longitudinal bars, all as hereinafter set forth.

The objects of our invention are, first, to

produce a triangular frame, of the class specied, in which the amount of steel used in its construction is minimized by so distributing or placing it that there is the most steel where the greatest load is sustained, the amount of steel decreasing as the load to be the same member in such a frame for both shear and tension, such member consisting of a twisted flat bar of special construction, and, third, to provide a frame which is adapted to support twisted steel floor rods, wire cloth, expanded metal, etc when used in connection with reinforced floors, thus making a unit system of reinforced floor construction.

Our frame is adaptable to girders of any size and of anyrequired strength and offers the least possible obstruction in the filling form to the concrete.

We attain the objects and secure the advantages above pointed out by the means illustrated in the accompanying drawings, in which Figure 1, is a top view of a frame embodying our invention; Fig. 2, a side elevation of said frame; Fig. 3, an end elevation of the same, and, Fig. 4, a cross-section taken at the center of the frame.

Similar letters refer to I similar parts throughout the several views.

Referring to the drawings it will be observed that theframe therein shown is made up of two bottom tension bars a and a to stay bar 1) extending the entire length of t e frame, said bar I) being remote from but parallel with said bars a and centrally placed relative thereto, fiat bars a fastened by pinch clips (1' to the bars a and riveted at-e to the barb, and triangular end ieces or tie braces f connecting the ends 0 the aforesaid bars a and b. Each end piece or brace f is twisted between the bars a, as shown in Fig. '3. Said braces are riveted to the bars a and b, a brace at each end of said bars, and these members produce a frame of triangular construction or formation. Holes 9 are made in the bar I) for the accommodation of rods used for floor slab reinforcement.

The bars ,0 are arranged in pairs, and the shortest pair is in the center, then comes a longer pair, and finally a still longer pair, three pairs in all, although this number may vary. Each of these pairs has a horizontal part and -is bent upward, outward and toward the longitudinal central plane of the frame at the terminals and twisted as shown. The bars are twisted in order to facilitate bending into position and for the purpose of affording a good gripor anchorage for the concrete. There is one full twist in each of the oblique terminals or parts of each bar 0. The horizontal parts of the longest pair of bars 0 lie against the inside faces of the bars a, correspondingparts of the intermediate pair lie"againsttheinside faces of the first mentioned horizontal parts, and the corrcsponding parts of the shortest pair lie against the insidecfaces of the intermediate horizontal p'arts, and the clips (1 secure the several horizontal contiguous members on each side noted, those on one side of the frame being fastened to said bar I) on the same side thereof, and those on the opposite side of the frame being fastened to said bar I) on the opposite side thereof. It will readily be understood that the members 0 constitute combination shear and tension bars which are eminently suited to reinforcing frames.

It is'clear from the foregoing that the com bined and united tension members in the center of the frame at the bottom present most steel in cross-section and consequently afford the maximum amount of strength at the place where it'is required, and the power of resistance'of the frame grows less from the central portion outward towards the ends thereof as the number of such tension members decreases. In other words, the strength of'the frame gradually decreases in propercomprising bottom tension members spaced ranged side by side and in contact with each the bottom tension members arranged in tion to the decrease in the load which it is calculated to sustain, from the maximum at the center to the minimum at the ends.

By providing more than one bottom tension bar on a side and more than one upper stay bar a frame can be produced which is capable of taking the place of I-beams in girders which have little depth and are of narrow breadth.

What we claim as our invention, and desire to secure by Letters Patent, is

' 1. A girder frame, of the class described,

apart, a top stay member, combination shear and tension members structurally independr. ent and separate from each other and from the bottom tension members, of unequal lengths, and having oblique terminals, the horizontal portions of said combination shear and tension members on each side and the corresponding bottom tension member being side by side and in contact with each other, means to fasten such contacting horizontal parts together, and means to fasten the free endsof said oblique terminalsito said top stay member.

2. A girder frame, of the class described, comprising bottom tension members spaced apart, a top stay member, combination shear I and tension members of unequal lengths and having twisted oblique terminals, the horizontal portions of said combination shear and tension members on each side and the corresponding bottom tension member being ar.

other, means to fasten such contacting horizontal parts together, and means to fasten the free ends of said twisted oblique terminals to said top stay member.

3. A girder frame, of the class described; comprising bottom tension members spaced apart, a top stay member, combination shear and tension members structurally independent and separate from each other and from pairs of unequal lengths and having oblique terminals, the horizontal portions of said 1 combination shear and tension members on each side and the corresponding bottom ten- 1 sion member being arranged side by side and in contact with each other, means to fasten such contacting horizontal parts together, and means to fasten the free ends of said oblique terminals to the sides of said top stay member.

4. A girder frame, of the class described, comprising bottom tension members spaced apart, a top stay member, combination shear and tension members arranged in pairs of un equal lengths and having oblique terminals, the horizontal portions of said combination the corresponding bottom .tension member being arranged side by side and in contact with each other, means to fasten such horizontal contacting parts together, means to fasten the free ends of said-oblique terminals to said top stay member, and inclined tie braces connecting the tension and stay members.

5. A-girder frame, of the class described, comprising bottom tension members spaced apart,-a top stay member, combination shear and tension members having oblique terminals, said combination shear and tension members connecting the top stay member with the bottom tension members, and'triangular end pieces or tie braces connecting the bottom tension members with the stay member and with each other.

6. A girder frame, of the class described,

comprisl'ng bottom tension members spaced apart, a top'stay member, combination shear and tension members having oblique terminals, said combination shear and tension members connecting the top stay member with the bottom tension members, and triangular end pieces or tie braces connecting the bottom tension members with the stay member and with each other, each of such braces having a twist therein between. the bottom tension members.

EDGAR N. SPAULDING. RALPH E. SPAULDING.

Witnesses WILLIAM A. GARDNER, LEROY H. Sums.

, shear and tension members on each side and 

